"You don't want to start a startup to do something that everyone agrees is a good idea, or there will already be other companies doing it. You have to do someth

"You don't want to start a startup to do something that everyone agrees is a good idea, or there will already be other companies doing it. You have to do something that sounds to most other people like a bad idea, but that you know isn't — like writing software for a tiny computer used by a few thousand hobbyists, or starting a site to let people rent airbeds on strangers' floors." Probably true more often than not, but Google and Facebook both started off doing something that everyone already thought was a good idea, they just did it much better.